安徽野生香菇遗传多样性及杂种优势的ISSR分析

采用简单序列重复区间扩增多态性(Inter–simplesequencerepeat,ISSR)技术,利用13个引物对26个安徽野生香菇Lentinulaedodes菌株和6个香菇栽培品种进行了遗传多样性分析,构建了遗传相关聚类图,并根据ISSR分析选择遗传距离远近不同的亲本进行组合杂交,评价了其杂种优势。在78个ISSR标记中,多态性标记为61个,占78.2%。聚类分析显示,当以相异距离0.23为阈值,32个菌株被划为5个ISSR遗传组,多数菌株之间遗传相似性较低。这表明供试菌株在DNA水平上存在比较显著的遗传变异,具有较丰富的遗传多样性。杂种优势的检测表明亲本间遗传距离较大的组合其杂种优势也较强。     

两系杂交水稻杂种优势研究 Ⅰ.主要经济性状表现

本研究观察了18个两系杂交水稻组合在华南地区种植时杂种优势表现。结果表明：三种类型两系杂交组合主要农艺性状优势强弱呈现出籼粳交＞籼爪交＞籼籼交＞三系杂交组合（对照）;同一杂交组合早晚季种植表现差异较大;亚种间杂种优势利用的主要问题是结实率和谷草比比较低。     

两系杂交水稻杂种优势研究：I.主要经济性状表现

本研究观察了１８个两系杂交水稻组合在华南地区种植时杂种优势表现。结果表明：三种类型两系杂交组合主要农艺性状优势强弱呈现出籼粳交〉籼爪交〉籼籼交〉三系杂交组合（对照）;同一杂交组合早晚季种植表现差异较大;亚种间杂种优势利用的主要问题是结实率和谷草比比较低。     

红松不同杂交组合种实形态与营养成分变异研究

为了解红松杂交子代种实性状变异规律,选育优良杂交组合,本文对44个不同杂交组合的红松种子的12个性状进行变异分析、相关分析、方差分析和主成分选择。结果表明：红松种实形态性状中种长变异系数最低,为10.65%,种子重变异系数最大,为36.35%。主要营养成分中油脂变异系数最低,为8.07%,多糖变异系数最高,为30.89%。相关分析表明种仁重、百粒重与种长呈正相关关系,通过选择种长较大的家系来提高种仁重与百粒重指标。44个不同杂交组合红松种实的形态性状与营养性状间均存在显著差异。通过主成分分析,选出3个综合性状优良的杂交组合,出仁率、种子重、百粒重、种仁重、油脂含量的现实增益分别达到7.52%、27.89%、13.14%、9.85%、10.08%,其中011×153出仁率、种子重、种仁重杂种优势最大,分别达到34.59%、95.75%和43.23%,156×161的百粒重与油脂含量杂交优势最大,为24.58%和24.87%。对具有相同亲本的杂交组合各性状进行杂种优势分析发现,以011为母本的杂交组合杂种优势较大,以174为父本的杂交组合杂种优势较大。红松不同杂交组合种实形态性状与营养成分存在丰富变异可供选择利用,为红松坚果林选育提供了理论与物质基础。     

大豆杂种优势利用研究 Ⅰ 杂交组合杂种优势的测定及高优势组合的初步筛选

利用优良的种质资源,通过对两年配制的199个大豆杂交组合F1代的杂种优势测定,得到杂交组合的杂种优势与单株荚数、单株粒数、主茎节数、分枝数相关显著,与双亲的综合性状关系密切。分析了各组合杂种优势的大小及规律,从中筛选出一批高优势组合。     

利用原生质体技术选育香菇优良菌株

通过拮抗试验、酯酶同工酶试验对6个香菇母本菌株进行分类.用原生质体单核化技术获取此6个菌株的单核体,进行两两杂交,获取15个杂交组合,并进行高温出菇试验和抗木霉试验.结果表明:在高温条件下有8个杂交组合能够出菇, 3、4、6号菌株产量相对高,与其他菌株差异极显著.1号、3号菌株与木霉的拮抗线均呈Ⅳ型,对木霉抗性强.因此,3号菌株属于耐温高抗品种,适合进行进一步的扩大试验.     

冬小麦粒叶比杂种优势及遗传效应分析

用9个冬小麦品种按5×4不完全双列杂交设计组配20个杂交组合,对小麦粒叶比的杂种优势和遗传效应进行分析。结果表明,小麦粒叶比表现出一定的杂种优势;一般配合力和特殊配合力方差均达极显著水平,说明亲本的粒叶比差异及杂交互作均对F1代产生遗传差异,该试验中石6021、农大99260080等的一般配合力较大,石6021×农大99260080、鲁麦14×济南17等组合的特殊配合力较大,产生了较强的杂种优势;粒叶比遗传符合加性-显性遗传模型,但以加性效应为主,其遗传决定度达87.65%,狭义遗传力为64.71%;在高粒叶比品种选育上应重视高粒叶比亲本筛选利用和杂交后代的早代选择。     

多子房性状应用于杂种小麦的研究——Ⅱ．多子房小麦的杂种优势与利用

利用3个多子房小麦与8个普通小麦品种杂交后获得的24个杂种及其相应的亲本材料,对多子房小麦的杂种优势与利用进行了研究。结果表明,F1各性状的杂种优势依次为株高＞穗粒数＞单株产量＞千粒重。单株产量有较强的杂种优势,18个组合超双亲均值,平均均产32．71％,12个组合有超标正优势,幅度为3．41－42．84％。多子房小麦杂种优势的主要表现是穗粒数增多,其生产应用还应注意加强对子房小麦其它农艺性状的改良。     

毛木耳种质资源的酯酶同工酶分析

采用垂直平板聚丙烯酰胺凝胶电泳技术对毛木耳56个菌株酯酶同工酶的酶谱多样性进行了研究。结果表明,56份材料有一定的遗传变异,共检测到迁移率不同的10条谱带,各菌株分别具有1~6条酶带,共有26种酶谱类型。菌株被分成了8大群:第一群包括黄耳zh等34个菌株;第二群包括白背木耳等8个菌株;第三、第四群分别为黑木耳和915两个单独的菌株;第五群包括99等4个菌株;第六群包括43等4个菌株;第七群包括50385和AP067两个菌株;第八群包括小上3和杂交34两个菌株。酯酶同工酶分析技术是鉴别种及品种以下菌株的有效手段。     

玉米杂种优势与几种酶活性关系

对８个杂交优势明显的玉米单交种进行过氧化物酶、过氧化氢酶活性的比较研究,结果表明：８个组合的杂种胚中过氧化物酶活性介于双亲之间,６个组合的杂种胚过氧化氨酶活性介于双亲之间,这可能与杂种中互补酶的存在有关。并测定了酸性磷酸脂酸的活性,４个组合杂种胚酶活性高于双亲,另外４个组合杂种胚活性介于双亲之间,表明酸性磷酸酯酶活性与杂种优势有一定相关性。     

毛木耳种质资源的RAPD分析

利用22个随机引物对来源不同的56个木耳菌株进行了RAPD分析。结果表明,所有引物的扩增产物DNA片段均表现出明显的多态性,供试菌株总共扩增出164条多态性片段,占总扩增片段的99%;供试菌株两两间的遗传相似系数变化较大(平均GS值0.2143￣0.8764)。采用系统聚类法中的类平均法,对供试的所有菌株两两间相似系数进行聚类,可将它们分为四大类,各大类的类间和类内菌株的遗传变异程度较大,以IV类内各菌株间的最高(平均GS值0.3891),II和III类间的最低(平均GS值0.5887),表明遗传变异也较丰富(总平均GS值0.4918)。将RAPD技术应用于不同菌株间遗传差异的研究,具有反应迅速、不受外界环境条件影响、能从DNA分子水平上揭示菌株间遗传差异等优点,是一种快速准确评估木耳种质资源的有效方法。     

云芝菌株遗传多样性的ISSR分析

来自全国的34株野生菌株经形态学特征和结合ITS序列鉴定为云芝。采用ISSR标记技术对34株野生云芝菌株进行遗传多样性分析。从20条引物中筛选出7条ISSR引物,扩增得到95个扩增位点,其中多态性位点88个。多态性位点占92.6%,表明ISSR标记的多态性非常高。基于ISSR条带构建亲缘关系树状图,其中遗传变异系数范围为0.58-0.91。34个云芝菌株在相似系数0.60时分为4个类群,不同菌株的遗传差异性与地理分布有一定联系。     

金针菇自交后代生物学特性的研究

选用6个生产用金针菇菌种(白色品种菌株F10、F4、FM、F21,黄色品种菌株F29、F3)分别进行自交,对其S1代自交群体的菌丝生长速度、产量、原基发生早晚、农艺性状进行综合分析。结果表明,自交导致后代群体的平均生长速度、平均产量降低。黄色自交子代菌株平均生长速度快于白色自交子代菌株。菌丝生长速度与产量不具有相关性,产量与现原基早晚有较强相关性,相同自交系中黄色品种现原基早于白色品种,F3菌株黄色后代现原基早于白色后代。在各菌株自交子代群体中,FM菌株子代具有高产优势,F3菌株子代有短菌龄优势,F10菌株子代有较好的商品表型特征,可根据育种目标选择自交子代群体中的优势菌株加以利用。     

金针菇子实体颜色的遗传规律研究

以金针菇黄色菌株F19和白色菌株F8801为亲本,原生质体单核化获得两亲本的单核菌株,配对杂交获得F1,从F1的子实体分离单孢菌株,与两亲本的原生质体单核化菌株进行回交配对,出菇观察子实体颜色,分析菇体颜色的遗传规律。研究结果表明,黄色为显性、白色为隐性,菇体颜色受一对基因(Cc)控制,与不亲和性因子A或B都没有连锁。     

Efficient production of intersubspecific hybrid mice and embryonic stem cells by intracytoplasmic sperm injection

Recently, mice and embryonic stem (ES) cells with allelic polymorphisms have been used extensively in the field of genetics and developmental biology. In this study, we examined whether intersubspecific hybrid mice and ES cells with these genotypes can be efficiently produced by intracytoplasmic sperm injection (ICSI). Frozen-thawed spermatozoa from wild-derived strains, JF1 (Mus musculus molossinus), MSM (M. m. molossinus), HMI (M. m. castaneus), and SWN (M. m. spp.), were directly injected into mature oocytes from laboratory mice ([C57BL/6 x DBA2]F1; M. m. domesticus). The in vitro and in vivo developmental capacity of F1 embryos was not significantly different among the groups (P > 0.05), and term offspring were efficiently obtained in all groups (27%-34% of transferred embryos). However, the mean body and placental weights of the offspring differed significantly with genotype (P < 5 x 10(-10)), with the HMI hybrid greatest in both body and placental weights. In an application study using these F1 offspring, we analyzed their mitochondrial DNA using intersubspecific polymorphisms and found the consistent disappearance of sperm mitochondrial DNA in the F1 progeny. In a second series of experiments, we generated F1 blastocysts by injecting MSM spermatozoa into C57BL/6 oocytes and used them to generate hybrid ES cell lines. The ES cell lines were established at a high efficiency (9 lines from 20 blastocysts) and their allelic polymorphisms were confirmed. Thus, ICSI using cryopreserved spermatozoa allows the efficient and immediate production of a number of F1 hybrid mice and ES cell lines, which can be used for polymorphic analysis of mouse genetics.     

Characterization of dextran-producing Leuconostoc strains

Leuconostoc strains were characterized according to their antibiotic susceptibilities, carbohydrate fermentation profiles, sucrase activity patterns and plasmid content. All the strains tested were resistant to the antibiotics sulphathiazole, trimethoprim and vancomycin, and could be separated into two groups based on whether or not they could ferment melibiose and raffinose. Six Leuconostoc strains possessed plasmids and many produced unique sucrase activity patterns in polyacrylamide gels. These data will aid in distinguishing among physiologically similar dextran-producing leuconostocs, frequently used in research and industry.     

Analyzing genetic relationships in Bombyx mori using intersimple sequence repeat amplification

Intersimple sequence repeat (ISSR) amplification was used to analyze genetic relationships among silkworm, Bombyx mori L., strains. Nineteen primers containing simple sequence repeat (SSR) motifs were tested for amplification on a panel of 42 strains, representative of the diversity of silkworm germplasm; 12 of the primers amplified distinct, reproducible bands. The primers amplified a total of 108 bands, of which 85 (78.7%) were polymorphic. The ISSR results suggested that within the dinucleotide class, the poly(CA) motif was more common than the poly(CT) motif. The ISSR amplification pattern was used to group the silkworm strains into seven subclusters based on their origin in an unweighted pair-group method with arithmetic average cluster analysis by using Nei's genetic distance. Seven major ecotypic silkworm groups were analyzed. Principal component analysis of the ISSR data supported the unweighted pair-group method with arithmetic average clustering. Therefore, ISSR amplification is a valuable method for determining genetic variability among silkworm varieties. This efficient genetic fingerprinting technique should be useful for characterizing the large numbers of silkworm strains held in national and international germplasm centers.     

香菇自然群体中个体间的空间分布及其遗传联系*

应用体细胞不亲和性反应、交配型因子分析和基因组ＤＮＡ的ＲＡＰＤ分析,研究了一个分布于方圆约１ｋｍ的６根倒木上的１８个香菇野生菌株间的遗传差异。结果表明,该群体大多数菌株间配对（８０．４％）体细胞不亲和,而同一倒木菌株间配对的体细胞亲和率达 ６２．５％。不同倒木菌株间未发现体细胞亲和的配对。该群体存在 １１个特异的Ａ因子和７个特异的Ｂ因子。同一倒木的菌株有的交配型因子相同,有的则不同。不同倒木的菌株大多数交配型因子不同,未发现交配型因子完全相同的菌株。ＲＡＰＤ分析显示,体细胞亲和的菌株,交配型因子完全相同的菌株,在基于ＤＮＡ相似系数的遗传相关聚类中,首先聚为小类。总起来看,在自然群体中,香菇个体间的遗传差异与其空间分布之间存在一定的联系,随着空间距离的增大,菌株间的异质性相应增高。     

Morphological characteristics of natural strains of certain species of basidiomycetes and biological analysis of antimicrobial activity under submerged cultural conditions

Twenty-one strains belonging to 18 species of basidiomycetes from different ecological groups of fungi were isolated from natural sources. Light and electron microscopy was used to determine the morphological properties of the cultures, which confirmed their classification as basidiomycetes and facilitated their identification in monocultures. The capacity of the fungal strains for biosynthesis of antibiotics was determined by one- or two-stage cultivation on seven nutrient media. It was established that, under submerged cultivation, antimicrobial substances were formed by 13 strains (81.25%) of 12 fungal species (Armillaria sp., Coprinus comatus, Flammulina velutipes, Hypsizygus ulmarius, Lentinus tigrinus, Lycoperdon pyriforme, Macrolepiota procera, Panellus serotinus, Pholiota aurivella, Pholiota lenta, Rhodocollybia maculate, and Sparassis crispa). The antibiotics formed were efficacious against bacterial test strains, including the methicillin-resistant strain Staphylococcus aureus (MRSA) and the strain Leuconostoc mesenteroides VKPM B-4177 that is resistant to the glycopeptide antibiotics. No antibiotic activity was revealed against fungal test cultures (Aspergillus niger INA 00760 and Saccharomyces cerevisiae RIA 259).